Electronic photographic developing device

ABSTRACT

The developing device consists of a developing tank and an archshaped developing tray and a similarly arch-shaped developing terminal. The developing solution is sent upwards onto the developing terminal by a pump and the toner in the developing solution is charged with the polarity opposite to he latent image charge on the photosensitive paper. The said toner flows from the developing terminal into the developing tray to a given level, and the photosensitive paper is sent through between the developing tray and the developing terminal. The surface of the developing tray includes ridges which diverge in the direction in which the photosensitive paper is sent, and the ridges are divided into two sets in such a way that the ridges of the first set come in between the ridges of the second set so that the developing solution may flow among the ridges. In the developing terminal on top of the developing tray are cut gutter-shaped holes, through which the developing solution flows in parallel with the longer sides of the developing terminal and approximately at right angles with the direction in which the photosensitive paper is sent. Parting strips are mounted parallel with the gutter-shaped holes.

United States Patent [72] Inventors Telzo Kushlma;

Masaya Ogawa, both of Abeno-ku, Qsalgadapan 2| Appl. No. 758,808 [22) Filed Sept. 10, 1968 [45] Patented Aug. 10, 1971 [73] Assignee Minolta Camera Kahushiki Kaisha Osaka, Japan [32] Priority Oct. 7, 1967,.Iau. 31, 1968 [33] Japan [31] 42/85,549 and 43/6,423

[54] ELECTRONIC PHOTOGRAPHIC DEVELOPING DEVICE 3 Claims, 7 Drawing Figs.

[52] US. Cl. 118/602, 118/428, 118/429, 118/612 [51] Int. L B05c 11/10 [50] Field of Search 118/637, 428, 602, 603; 95/96, 89; 117/37 [56] References Cited UNITED STATES PATENTS 2,993,427 7/1961 Lovercheck 95/96 3,107,596 10/1963 Arnold et al.... 95/89 3,148,611 9/1964 Eisner et al. 95/89 3,163,099 12/l964 Limberger 355/107 3,249,088 5/1966 Ostensen 118/637 Primary Examiner-Morris Kaplan Attorney-Watson, Cole, Grindle and Watson ABSTRACT: The developing device consists of a developing tank and an arch-shaped developing tray and a similarly archshaped developing terminal. The developing solution is sent upwards onto the developing terminal by a pump and the toner in the developing solution is charged with the polarity opposite to he latent image charge on the photosensitive paper. The said toner flows from the developing terminal into the developing tray to a given level, and the photosensitive paper is sent through between the developing tray and the developing terminal. The surface of the developing tray includes ridges which diverge in the direction in which the photosensitive paper is sent, and the ridges are divided into two sets in such a way that the ridges of the first set come in between the ridges of the second set so that the developing solution may flow among the ridges. In the developing terminal on top of the developing tray are cut gutter-shaped holes, through which the developing solution flows in parallel with the longer sides of the developing terminal and approximately at right angles with the direction in which the photosensitive paper is sent. Parting strips are mounted parallel with the gutter-shaped holes.

PATENTEDAUGIOISYI 3,598,086

SHEET 1 0F 3 mill ELECTRONIC PHOTOGRAPHIC DEVELOPING DEVICE BACKGROUND OF THE INVENTION In the conventional wet-type developing device, the developing solution in the developing tank is pumped upwards into the developing terminal which charges the toner in the developing solution, and then the developing solution flows into the developing tray to a given level. The photosensitive paper with the electric latent image is sent through between the developing terminal and the developing tray. In this conventional construction, however, the photosensitive paper, which is made soft by being dipped in the developing solution, easily wrinkles as it passes through the developing tray, and because of the wrinkles some parts of the photosensitive paper cannot be in constant contact with the fresh developing solution and some development unevenness and irregularities result. In some cases the said wrinkles are made into folds as the photosensitive paper passes through the drying and carrying out rollers, and the development is unsatisfactory. Also in the conventional developing device, enough care has not been taken to constantly supply the fresh developing solution with a uniform density to the photosensitive surface of the photosensitive paper, so that the density of the developing solution drops quickly where the developing solution is in contact with the dark parts (the parts where much toner is to be attached) of the photosensitive paper and this has caused the drop in the contrast with the light parts. Further, if the photosensitive paper touches the developing terminal as it is sent between the developing terminal and the developing tray, the electric latent image on the photosensitive paper is electrically damaged and also the image formed by the toner that has attached onto the photosensitive paper is mechanically damaged by friction. In the conventional developing device no special care has been taken to prevent the said defects except merely to widen the space between the developing terminal and the developing tray, which increases the height of the developing device without succeeding in completely preventing the contact of the photosensitive paper with the developing terminal.

SUMMARY OF THE INVENTION In the present invention, the defects of the conventional wet-type developing device are overcome. For the purpose of preventing the wrinkles and achieving a uniform image with a clear contrast, component forces that extend the photosensitive paper in the directions at right angles with the direction in which the photosensitive paper passes are applied to the photosensitive paper as it is dipped in and sent through the developing tray. These component forces are applied by the ridges on the surface of the developing tray that diverge in the direction in which the photosensitive paper passes. The ridges prevent wrinkling of the photosensitive paper. Also the ridges are divided into two sets in the direction in which the photosensitive paper passes in such a way that the ridges of the first set come in between the ridges of the second set so that the developing solution may flow among the spaces between the ridges. Further, in the developing terminal are cut guttershaped holes through which the developing solution flows approximately at right angles with the direction in which the photosensitive paper passes. From these gutter-shaped holes the fresh developing solution is supplied and at the same time the pressure from the flowing solution prevents the photosensitive paper from touching the developing terminal.

The primary object of the present invention is to provide a developing device for developing photosensitive paper while extending the photosensitive paper so as to prevent wrinkling.

Another object of the present invention is to provide an electronic photograph developing device for supplying fresh developing solution in uniform concentration uniformly and properly to the photosensitive face of a photosensitive paper.

Still another object of the present invention is to provide an electronic photograph developing device for effecting the proper mixing of developing solution in the developing tray.

And yet another object of the present invention is to provide a developing device for facilitating the new supply of developing solution.

And yet still another object of the present invention is to provide an electronic photograph developing device easy to disassemble and assemble.

Other objects, advantages and features of the present invention will be understood by the following detailed description of the preferred embodiment taken with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWING FIG. I shows the front cross section of a preferred embodiment of the present invention, FIG. 2 illustrates the side cross section of the same preferred embodiment and the related position of the carrying rollers and the photosensitive paper, FIG. 3 shows a perspective view of the developing tank of the same preferred embodiment, FIG. 4 illustrates the front cross section of the tank, FIG. 5 shows a perspective view of the developing tray of the preferred embodiment, FIG. 6 illustrates the top view of the developing tray, and FIG. 7 shows a perspective view of the developing terminal of the preferred embodiment.

DESCRIPTION OF THE PREFERRED EMBODIMENT FIGS. 1 and 2 show the entire construction of the photoelectric developing device according to the present invention, and FIG. 2 in particular shows the related position of the carrying rollers and the carrier photosensitive paper in the present developing device.

As shown in the Figures, the photoelectric developing device consists of the developing tank A forming the lower part, the developing tray B and the developing terminal C. The developing tank A consists of the vertical sideplates l, 1, the inclined sideplates 2, 2, the vertical sideplates 3, 3 on both ends, and the bottom plate 4. The bottom plate 4 is inclined at the angle a (FIG. 4) and the hollow at the deepest-part forms the pump chamber 7. The projecting tables 5 project horizontally towards the inside of the tank from the borders of the vertical sideplates I and the inclined sideplates 2, so that on these projecting tables 5 the developing tray B is to be placed horizontally. The other side of these projecting tables 5 form indentations 6 which facilitate the drawing of the developing device out of the photoelectric duplicating machine for the purpose of changing and supplying the developing solution and cleaning.

As has been stated above, the developing tray B is to be placed horizontally on the projecting tables 5 of the developing tank A, and as is shown in FIGS. 5 and 6 the body of the developing tray B consists of the developing chamber 8 through which the photosensitive paper is sent and the gutter 12 which lies in parallel with the said developing chamber 8 and directly under the photosensitive paper drying and carrying out rollers 38 and 38' (see FIG. 2). At one end of the tray are the motor seat 10 and the developing solution supply tank 9.

The developing chamber 8 is in the shape of a cylindrical arch with the lowest central part and high front and back edges along which are drainage holes 11. Between one row of drainage holes 11 and the other are the ridges'IS, 16 which diverge in the direction in which the photosensitive paper 39 passes, and as the photosensitive paper passes through the developing tray it is in contact with these ridges 15, 16 and is extended by them in the directions at right angles with the direction in which it passes and thus wrinkling of the photosensitive paper is prevented.

The ridges are divided into two sets at the center of the developing tray and the ridges 15 of the first set are arranged in between the ridges 16 of the second set so that the two sets of ridges do not form one continuous set of ridges. Because of this arrangement, the developing solution can flow and mix among the spaces between these ridges and a uniform density can be maintained. That is to say, when that part of the image on the photosensitive paper which passes through one space between two ridges 15, of the first set happens to be a dark part which is densely charged and attracts much toner, the density of the developing solution in the said space gets lower than that in the other spaces and there remains less toner to attach to the photosensitive paper thereafter, but where the ridges are divided into two sets the developing solution mingles and flows in from the other spaces and fresh toner is supplied into the said space, so that development is achieved uniformly.

On the motor seat 10 is fixed the motor 24 from which leads vertically downwards the shaft 23 through the hole 18 in the motor seat 10. As the developing tray B is placed on the projecting tables 5 of the developing tank A, the pump 21 in the pump chamber 7 of the developing tank A is connected with the lower end of the said shaft 23 and is driven by the motor 24 through the shaft 23.

The pipe 25 whose one end is connected with the spout 22 of the said pump 21 projects into the developing chamber 8 through the hole 26 at the bottom of the developing chamber 8. There is a gap between the hole 26 and the pipe 25 through which some small amount of developing solution flows from the'developing chamber 8 back to the developing tank A, so that when the pump 21 stops there remains no developing solution inside the developing chamber 8.

in the developing solution supply tank 9 is the hole which lets drip into the developing tank A the toner to be supplied, and also in the gutter 12 is the small hole 13 which lets fall back to the developing tank A the developing solution gathered in the gutter.

Onto mounting indents 17 in both of the sideplates of the developing chamber 8 are fitted the projecting pieces 31, 31 of the developing terminal C which is described below, so that the developing terminal C may come into the right position on the developing chamber 8.

As to the developing terminal C, the metal terminal plate 28 is in the shape of the cylindrical arch similar to the cylindrical arch of the developing chamber 8, and along with the sideplates 29 forms the vessel for the developing solution. The front edge of the metal plate 28 is made lower than the other edge as is shown by 33 so that the excessive developing solution may overflow into the developing chamber. In the cylindrical arch-shaped terminal plate 28 are set the parting strips 34, 34, which are lower in height than the front and back edges of the metal terminal plate 28, approximately at right angles with the direction in which the photosensitive paper passes. ln the outside of these parting strips 34 and approximately in parallel with them are cut the gutter-shaped holes 36, 36 through which the developing solution flows onto the photosensitive paper 39. The supply pipe 27, of which. one end is connected with the aforesaid pipe that projects into the developing chamber 8, goes through a hole in the cylindrical arch-shaped plate 28 and the other end of the pipe 27 is open between the parting strips 34, 34.

The drainage holes 35 in the lower edges of the parting strips 34 and the drainage hole 32 at the lowest part of the cylindrical arch-shaped terminal plate 28 prevent the developing solution from remaining on the cylindrical arch-shaped terminal plate 28 when the pump 21 stops.

On the sideplate 29, 29 of the cylindrical arch-shaped terminal plate 28 are fixed the supporting pieces 30. 30 with the projecting pieces 31, 31 which are to fit, as described above, into mounting indents 17 17 on the sideplates of the developing chamber 8.

Owing to the construction described above of the present invention, the developing solution with uniform density which is sent upward by the pump 21 flows in between the parting strips 34, 34 of the cylindrical arch-shaped terminal plate 28 out of the mouth of the supply pipe 27, and the gushing developing solution becomes of still more uniform density as it flows over the parting strips, and it flows downthrough the gutter-shaped holes 36, 36 onto the whole width of the photosensitive paper 39 that is being sent through, so that the resh developing solution is constantly supp ied onto the photosensitive paper 39 in the developing chamber 8. At the same time the pressure of the developing solution that is flowing down onto the photosensitive paper 39 prevents the paper 39 from coming into contact with the cylindrical arch-shaped terminal plate 28. The excessive developing solution flows down to the developing chamber 8 over the lower front edge (See 33) of the cylindrical arch-shaped terminal plate.

The excessive developing solution in the developing chamber flows down through the drainage holes 11 along the front and back edges of the developing chamber 8 back to the developing tank A to circulate through the pump, so that a given level is maintained in the chamber 8.

Thus the fresh developing solution with a uniform density can be constantly supplied onto the photosensitive paper 39 which is being sent through the developing chamber 8 being extended and prevented from wrinkling by the ridges 15, 16. And because of the pressure of the developing solution the photosensitive paper can be sent through without contacting the developing terminal, so that a clear image can be faithfully developed.

We claim:

1. A photographic device for developing photosensitive paper, comprising;

a developing tank including a supply of developing fluid and a pump for circulating said fluid,

a developing tray mounted on said developing tank, said developing tray including an arcuate top member having a plurality of ridges extending substantially at right angles to the longitudinal axis of said top member,

said ridges are divided are divided into two sets of interleaved element extending along each side of said top member to provide mixing of said developing fluid,

a developing terminal mounted in spaced relationship to said developing tray above said arcuate top member, said terminal including a bottom surface arcuately shaped to conform to said arcuate top member whereby an arcuate opening is formed between said arcuate members,

a conduit interconnecting said developing tank and said developing terminal to provide developing fluid thereto,

said developing tray further including a gutter having a discharge hole therein formed along an edge of said opening to catch fluid from said photosensitive paper as it leaves said opening,

said developing terminal including slotted channels in said bottom surface extending parallel to the axis of said developing terminal to allow developing fluid to flow onto said photosensitive paper which is fed axially into said opening and supported on its bottom surface by said ridges, and

said developing terminal further including spaced parting strips extending parallelly with said slotted channels.

2. A device as in claim 1 wherein said developing tank further includes a motor for driving said pump.

3. A device as in claim 1 wherein said developing tank further includes mountings and said developing tray includes projections engaging said mountings for mounting said tray on said tank. 

1. A photographic device for developing photosensitive paper, comprising; a developing tank including a supply of developing fluid and a pump for circulating said fluid, a developing tray mounted on said developing tank, said developing tray including an arcuate top member having a plurality of ridges extending substantially at right angles to the longitudinal axis of said top member, said ridges are divided into two sets of interleaved elements extendinG along each side of said top member to provide mixing of said developing fluid, a developing terminal mounted in spaced relationship to said developing tray above said arcuate top member, said terminal including a bottom surface arcuately shaped to conform to said arcuate top member whereby an arcuate opening is formed between said arcuate members, a conduit interconnecting said developing tank and said developing terminal to provide developing fluid thereto, said developing tray further including a gutter having a discharge hole therein formed along an edge of said opening to catch fluid from said photosensitive paper as it leaves said opening, said developing terminal including slotted channels in said bottom surface extending parallel to the axis of said developing terminal to allow developing fluid to flow onto said photosensitive paper which is fed axially into said opening and supported on its bottom surface by said ridges, and said developing terminal further including spaced parting strips extending parallelly with said slotted channels.
 2. A device as in claim 1 wherein said developing tank further includes a motor for driving said pump.
 3. A device as in claim 1 wherein said developing tank further includes mountings and said developing tray includes projections engaging said mountings for mounting said tray on said tank. 